Table 1.

Frequency of occurrence of the up to four salt bridges in the membrane-proximal region for each TMD system^[a].

Salt bridge	αIIbβ3 TMD			αvβ3 TMD			α5β1 TMD
	SimI	SimII	SimIII	SimI	SimII	SimIII	SimI	SimII	SimIII
R995-D723	47	92	35	57	8	46	14	66	38
	58 ± 6.7[b]			37 ± 14.8[b]			39 ± 15.0[b]
R995-E726	47	50	2	70	29	18	24	78	24
	33 ± 15.5[b]			39 ± 18.8[b]			42 ± 18.0[b]
R997-D723	23	95	23	84	52	7	—[c]	—[c]	—[c]
	47 ± 24.0[b]			48 ± 22.3[b]			—[c]
R997-E726	10	39	2	10	31	51	—[c]	—[c]	—[c]
	17 ± 11.2[b]			31 ± 11.8[b]			—[c]

^[a]In %.

^[b]Mean values and SEM (eq. 6), calculated over three MD simulations.

^[c]Interactions that cannot be formed in the TMD of integrin α₅β₁.